Fix several typos in sdk/lib/internal/internal.dart
Fix several typos in sdk/lib/internal/internal.dart

I've fixed a few typos in the mentioned module while flicking through the dart built-in libraries.

Closes https://github.com/dart-lang/sdk/pull/49015

GitOrigin-RevId: c8660e7932a647bd018a838629a8e1a28b41c90e
Change-Id: I7fae4702f6ee640561f5ebbbf68100f6abe8c360
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/244940
Reviewed-by: Michael Thomsen <5977a55c75bb4612004451a56b0b4c22d9d3311d@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk